Contained rupture of a renal hydatid cyst into the perirenal space: An uncommon radiologic finding

Less than 5% of all localizations of echinococcosis are renal hydatid cysts, making them uncommon manifestations. It is exceptional when there is a contained rupture in the perirenal space. We report the case of a 47-year-old woman with chronic left flank pain, who has a rural exposure to dogs, and has imaging findings of a multiloculated renal cystic lesion that appears to have ruptured into the perirenal space. This case illustrates the importance of cross-sectional imaging and the diagnostic difficulty of atypical renal echinococcosis. CT is essential for identifying rupture, and hydatid disease should be taken into account when making a differential diagnosis of complex renal cystic masses in endemic areas.